### From: Rahul Pendse <rpendse@trinityconsultants.com>

Sent: Tuesday, August 13, 2013 7:46 PM

To: Krivo, Stan

Cc: Kathryn.Maness@anadarko.com; Sara.Carlson@anadarko.com;

Land, Eva; Fortin, Kelly

Subject: RE: Anadarko OCS Permit Application

Hello Stan,

Sara Carlson of Anadarko had a phone discussion with Kelly Fortin and Eva Land in the last week about the OCS PSD/Title V permit applications Anadarko is planning to submit in the near future. After the discussions with EPA, I was informed by Anadarko that they would like to apply for two permanent OCS PSD/Title V permit (i.e., renewable every five years) for the "Blackhawk" and the "Blackhornet" drillships. Also, Anadarko will be applying for a temporary 2

- year PSD/Title V permit for the "Bob Douglas" dril lship. I wanted to inform you about the recent changes since we had communicated previously about Anadarko's proposal for the temporary source permits for Blackhawk and Blackhornet drillships,

For a temporary OCS permit application, the air dispersion m odeling will be performed using the approach discussed in the emails below.

For the permanent OCS permit applications, the air dispersion modeling will be performed per air dispersion modeling protocol reviewed by you. For reference, I will provide you w ith a revised protocol with your comments incorporated and additional revisions based on our follow up phone discussions.

Please let me or Sara Carlson know if you have any questions about the proposed air dispersion modeling approaches or if we could be of help.

Best Regards,

Rahul Pendse

----------------------------------------------------------------------------------------------------------------------------- --------

Rahul Pendse │ Managing Consultant│rpendse@trinityconsultants.com

Trinity Consult ants │ 301 Main Street, Suite 900 │Baton Rouge, LA 70825

Office: 225

- 346

- 4003 │ Fax: 225

- 346

- 4032 │ Cell: (714) 454

- 0518

From: "Krivo, Stan" < Krivo.Stanley@epa.gov > To: Rahul Pendse < rpendse@trinityconsultants.com >, Cc: " Sara.Carlson@anadarko.com " < Sara.Carlson@anadarko.com >, " Kathryn.Maness@anadarko.com "

< Kathryn.Maness@anadarko.com > Date: 08/08/2013 01:32 PM Subject: RE: Temporary OCS source Class I Modeling Approach

Rahul,

Given the proposed temporary OCS project will be in the same l ease blocks as provided in the May 2013 AirQuality Modeling Protocol for the EGOM Completion and Maintenance Project, the previous provided (i.e.,

10/11/12 email below) procedure of modeling the worst

- case emissions for both the drilling and support vesse ls
from a single drilling vessel stack at the drilling vessel’s worst

- case impact location would be acceptable.

Please note that a new temporary source OCS PSD application should consider and/or address:

- PM2.5 emissions (including secondary ) and impacts, as appropriate

- January 2012 court decision concerning the use of PM2.5 SIL and SMC

- Use of CALPUFF for impact assessment

I assume that issue with the support vessel volume source modeling in the previous May 2013 m odeling protocol is
no longer of concern so your note concerning a separate email on this issue will not be sent.

Thanks...sjk

From: Rahul Pendse [ mailto:rpendse@trinityconsultants.com ]

Sent: Thursd ay, July 18, 2013 4:21 PM

To: Krivo, Stan

Cc: Sara.Carlson@anadarko.com ; Kathryn.Maness@anadarko.com Subject: Re: Temporary OCS source Class I Modeling Approach

Stan,

Thanks for your time in discussing the air dispersion modeling protocol. Per our discussion, Anadarko will utilize previously approved approach of modeling worst

- case project emissions (i.e., emissions from drilling and support vessels) from a single drilling vessel stack at the worst

- case location (i.e., nearest from the Class I area receptor) for the proposed temporary (i.e., operations 2 year or less) OCS

source. See your email below for re ference. Please respond to this email when you get a chance.

Thanks.

P.S.

- I will send you a separate email summarizing our discussions about 'Volume Source Set Up' and

associated emission rate.

Best Regards,

Rahul Pendse

---------------------------- ---------------------------------------------------------------------------------------------------------

Rahul Pendse │ Managing Consultant│rpendse@trinityconsultants.com

Trinity Consultants │ 301 Main Street, Suite 900 │Baton Rouge, LA 70825

Office: 225

- 346

- 4003 │ Fax: 225

- 346

- 4032 │ Cell: (714) 454

- 0518

----- Forwarded by Rahul Pendse/Trinity Consultants on 07/18/2013 03:11 PM

-----

From: Stanley Krivo < Krivo.Stanley@epamail.epa.gov > To: Rahul Pendse < rpendse@trinityconsultants.com >, Date: 10/11/2012 10:48 AM Subject: Re: Class I Modeling Approach



### Rahul,

### For temporary OCS drilling sources the PSD regulation 40 CFR 52.21(i)(3) provides exemptions

from the normal NAAQS and PSD increment analyses, pre

- and post

- construction monitoring, and additional impact anal yses requirements. To qualify for the exemption the project allowable emission must impact no Class I area and no area where the applicable increment is known to be

violated.

My understanding is that your proposed OCS source would be temporary, have the s ame PSD pollutants, and be located in the same general area as that for ENI and BHP Billiton permit applications. Because of the distance to the nearest Class I area and the fact that the Class I area impacts of concern are the AQRV and PSD increments (i.e ., 24

- hour and annual averaging periods), the procedure of modeling worst

- case project emissions (i.e., emissions from drilling and support vessels) from a single drilling vessel stack at the worst

- case location used in the ENI and BHP Billiton application s would be acceptable. [Note this modeling procedure may not be acceptable for non

- temporary OCS PSD applications.]

Please let me know of any questions

. ...sjk

Stanley J. Krivo US Environmental Protection Agency, Air Planning Branch

Atlanta Federal Cente r, 61 Forsyth Street, SW Atlanta, Georgia 30303

404/562

- 9123 (Phone) 404/562

- 9019(Fax)

Rahul Pendse

-- - 10/10/2012 06:21:31 PM

--- Stan, Thanks for your time to discuss Class I modeling approach with me. To

From: Rahul Pendse < rpendse@trinityconsultants.com > To: Stanley Krivo/R4/USEPA/US@EPA

Date: 10/10/2 012 06:21 PM Subject: Class I Modeling Approach

Stan,

Thanks for your time to discuss Class I modeling approach with me. T o further clarify our discussion about Class I modeling yesterday, I was proposing to use the modeling approach specified in the

attached determinations based on which OCS

- EPA

- R4007 and OCS

- EPA

- R4008 were approved.

 Please refer to Section 9.4.2 of the att ached document

 Please refer to Section 7.2.2 of the attached document

Let me know if you would like to discuss further after you get a chance to review the attached documents. Thanks again and I look forward to hearing from you. Have a good rest of the week.

Best Regards,

Rahul Pendse Managing Consultant | Trinity ConsultantsPhone: 949

- 296

- 4100 Ext. 106 | Cell: 714

- 454

- 0518



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